BBN has its roots in an initial partnership formed on October 15, 1948 between Leo Beranek and Richard Bolt, professors at the Massachusetts Institute of Technology[4]. Bolt had won a commission to be an acoustic consultant for the new United Nations permanent headquarters to be built in New York City. Realizing the magnitude of the project at hand, Bolt had pulled in his MIT colleague Beranek for help and the partnership between the two was born. The firm, Bolt and Beranek, started out in two rented rooms on the MIT campus. Robert Newman would join the firm soon after in 1950, and the firm became Bolt Beranek Newman.[5] Beranek remained the company's president and chief executive officer until 1967, and Bolt was chairman until 1976.

J. C. R. Licklider joined BBN as vice president in Spring 1957.[6] Foreseeing the vast potential of digital computers, Licklider convinced the BBN leadership to purchase a then state-of-the-art Royal McBeeLGP-30 digital computer at the price of $30,000, the most expensive piece of research equipment BBN had ever bought. Within a year of the computer's arrival, BBN had a visit from Ken Olsen, president of the newly formed Digital Equipment Corporation. DEC had just built a prototype of its first computer, the PDP-1, and Olsen persuaded BBN to test it out. After numerous suggestions from Licklider, engineer Ed Fredkin, and several others, DEC was able to begin production of the PDP-1.[5] The first produced PDP-1 was also purchased by BBN, and was delivered in November 1960.[7]

Once the PDP-1 arrived, BBN hired John McCarthy and Marvin Minsky as consultants. McCarthy had been unsuccessful in convincing MIT engineers to build time-sharing systems for computers. He had more success at BBN though, working with Ed Fredkin and Sheldon Boilen in implementing one of the first timesharing systems, the BBN Time-Sharing System.[8] In 1962, BBN would install one such time-shared information system at Massachusetts General Hospital where doctors and nurses could create and access patients' information at various nurses' stations connected to a central computer.[5]

Dr. Talib Hussain, senior scientist at BBN Technologies, looks over the shoulder of a recruit during a training session on the Virtual Environments for Ship and Shore Experiential Learning system at Recruit Training Command.

The substantial calculations required for acoustics work led to an interest, and later business opportunities, in computing. BBN was a pioneer in developing computer models of roadway and aircraft noise, and in designing noise barriers near highways.[14]
Some of this technology was used in landmark legal cases where BBN scientists were expert witnesses.[15]

BBN was a key participant in the creation of the Internet. It was the first organization to receive an Autonomous System Number (AS1) for network identification.[27] ASNs are an essential identification element used for Internet Backbone Routing; lower numbers generally indicate a longer established presence on the Internet. AS1 is now operated by Level 3 Communications following their acquisition of BBN's Genuity internet service provider. BBN registered the bbn.com domain on April 24, 1985, making it the second oldest domain name on the internet.[28][29] In addition, BBN researchers participated in the development of TCP, created the Voice Funnel, an early predecessor of voice over IP, helped lead the creation of the first email security standard, Privacy Enhanced Mail (PEM), chaired development of the "core" Internet Protocol security suite (IPsec) standards, and performed extensive work to secure the Border Gateway Protocol (BGP).

In the 1970s, BBN created Telenet, Inc., to run the first public packet-switched network.

In 1983 BBN Instruments was sold to Vibro-Meter Corp.

In 1989, BBN's acoustical consulting business was spun off into a new corporation, Acentech Incorporated, located across the street from BBN headquarters in Cambridge.[32]

In 1994 LightStream Corp., a joint venture with Ungermann-Bass, Inc. created in 1992 to manufacture asynchronous transfer mode (ATM) switches, was sold to Cisco Systems Inc. $120 million.

BBN formed an early Internet service provider in 1994 as its BBN Planet division.[33] Previously traded as "BBN" on the stock market, the company was purchased by GTE in 1997 as a wholly owned subsidiary.[34] BBN Planet was joined with GTE's national fiber network to become GTE Internetworking, "powered by BBN". When GTE and Bell Atlantic merged to become Verizon in 2000, the Internet service provider division of BBN was included in assets spun off as Genuity to satisfy Federal Communications Commission (FCC) requirements, leaving behind the remainder of BBN Technologies. Genuity was later acquired out of bankruptcy by Level 3 Communications in 2003.[35] In March 2004, Verizon sold the remainder of the company, by then known as BBNT Solutions LLC, to a group of private investors from Accel Partners, General Catalyst Partners, In-Q-Tel and BBN's own management,[36] making BBN an independent company for the next five years.

In September 2009, Raytheon entered into an agreement to acquire BBN as a wholly owned subsidiary.[37] The acquisition was completed on October 29, 2009[38] and the company was valued at approximately $350 million.[39] From July 2019, the domain name bbn.com, the second oldest currently registered domain name on the Internet, is redirected to www.raytheon.com/capabilities/innovation.

Digital Force Technologies (DFT) of San Diego, California was a wholly owned BBN subsidiary, purchased in June 2008, and spun out in 2018.[40]

Former BBN employees have formed about a hundred startup companies with varying levels of official involvement, including Parlance Corporation and EveryZing.[41]

^Roberts, Dr. Lawrence G. (May 1995). "The ARPANET & Computer Networks". Archived from the original on 24 March 2016. Retrieved 13 April 2016. Then in June 1966, Davies wrote a second internal paper, "Proposal for a Digital Communication Network" In which he coined the word packet,- a small sub part of the message the user wants to send, and also introduced the concept of an "Interface computer" to sit between the user equipment and the packet network.